Pass XA25?

[pozo1992]

For the interested, here the manual from the internet http://www.moremusic.nl/pass_labs/Manuals/Manual-XA25.pdf

Yesterday I discovered that the first review (in dutch and english) has been put on the above mentioned web-site. Some pictures of the guts too.....

 

[Michael Rothacher]

That's an impressive little amplifier. Pretty pics in the manual too.

 

[Zen Mod]

and values of these big honkin' 50-watters will surprise everyone ....... at least that was the case with me

 

[pozo1992]

and values of these big honkin' 50-watters will surprise everyone ....... at least that was the case with me

You`ve been able to read the values? Would you mind sharing?

 

[WalterW]

1 Ohm / 50Watt?
Both wires go to the PCB, so probably the R in CRC.
Frontend maybe VFET pt2 alike? With the 2sa1837 and 2sc4793, 2sk170/2sj74 input JFETs of course, with 2sj313 and 2sk2013 on the little heatsinks.

I want to build that one! My hands are itching.....

 

[pozo1992]

1 Ohm / 50Watt?
Both wires go to the PCB, so probably the R in CRC.
Frontend maybe VFET pt2 alike? With the 2sa1837 and 2sc4793, 2sk170/2sj74 input JFETs of course, with 2sj313 and 2sk2013 on the little heatsinks.

I want to build that one! My hands are itching.....

Many new questions arise: Why so many caps on the front-end-board? Decoupling, boot-strapping, part of the biasing scheme?
Are 50W/1R part of the biasing scheme? ......
Now that we know the transistors of the front-end: Is cascode-feedback applied plus does this help stabilizing the idle current of the toshiba MOSFETs?

 

[MASantos]

Could someone share a link for the review?

 

[kasey197]

http://moremusic.nl/reviews/passlabs/XA25/review-PassLabs_XA25-music-emotion.pdf

in english after the first few pages

 

[Nelson Pass]

I like the "XA25 goes with straight hair on the arms" part.

 

[gl]

And the part that talks about "a pack of infected mushroom".

Graeme

 

[PKI]

Imo that's was the best sounding amp at Axpona 17.

 

[jelt2359]

I penned my thoughts on the XA25 in comparison with the F7 here:

theheadphonelist.com/pass-labs-xa25-vs-first-watt-f7-the-two-newest-nelson-pass-amplifiers-go-head-to-head/

Glad to see some reviews making it out there now, they weren't available when I bought these two amps so hopefully this helps someone out there as well.

 

[Zen Mod]

You`ve been able to read the values? Would you mind sharing?

I'm wearing da spectacles from my tender age ....... so , no - I wasn't able to read values from that pdf

however - one thing is repeating ........ Papa is again mocking plenty of our beliefs - what is Kosher and what's not , in amplifier construction

if nothing else - there is more optocouplers and caps than transistors .......

 

[Soundhappy]

http://moremusic.nl/reviews/passlabs/XA25/review-PassLabs_XA25-music-emotion.pdf

in english after the first few pages

Thanks for the link of interesting review.
Haha power wirewound resistors inside

 

[kasey197]

I penned my thoughts on the XA25 in comparison with the F7 here:

theheadphonelist.com/pass-labs-xa25-vs-first-watt-f7-the-two-newest-nelson-pass-amplifiers-go-head-to-head/

Glad to see some reviews making it out there now, they weren't available when I bought these two amps so hopefully this helps someone out there as well.

thanks nice writing you should contribute to a magazine

 

[kasey197]

Thanks for the link of interesting review.
Haha power wirewound resistors inside

I am guessing we will see bigger versions of this amp at some point

I am also wondering what those big resistors are for ?

Nelson can you drop us a hint or two ?

 

[Nikon1975]

I have two questions:
1) How can a SE amp be X? From my understanding the X configuration applies only to balanced design.
2) As Nelson mentioned in the manual, what Furitech connectors Passlabs is using?

Thanks,

Davide

 

[Zen Mod]

1. don't be so picky ......

 

[Dennis Hui]

2) They look like these:

FT-807(R) & FT-807(G) | FURUTECH

Note they are not the same as the ones on, for example, the XA30.8.

 

[Nikon1975]

What's on the 30.8?

D